They should not get motion sickness. IF there is a case where they do, they can't get sick to their stomachs and puke like we can. The worst that would happen is they would stress, and in that scenario, they may poop or skip a meal. But that can be monitored by offering water every 3-4 hours, and over a long trip, getting out and lunging them for 10mins or so to get some exercise every 6-8 hours would be good. Otherwise, no, I can't see one getting sick.
at 11:15 AM on Apr. 2, 2010